import numpy as np
import typing
from typing import Any

from rasa.nlu.config import RasaNLUModelConfig
from rasa.nlu.featurizers import Featurizer
from rasa.nlu.training_data import Message, TrainingData

if typing.TYPE_CHECKING:
    from spacy.language import Language
    from spacy.tokens import Doc


def ndim(spacy_nlp: "Language") -> int:
    """Number of features used to represent a document / sentence."""
    return spacy_nlp.vocab.vectors_length


def features_for_doc(doc: "Doc") -> np.ndarray:
    """Feature vector for a single document / sentence."""
    return doc.vector


class SpacyFeaturizer(Featurizer):

    provides = ["text_features"]

    requires = ["spacy_doc"]

    def train(
        self, training_data: TrainingData, config: RasaNLUModelConfig, **kwargs: Any
    ) -> None:

        for example in training_data.intent_examples:
            self._set_spacy_features(example)

    def process(self, message: Message, **kwargs: Any) -> None:

        self._set_spacy_features(message)

    def _set_spacy_features(self, message):
        """Adds the spacy word vectors to the messages text features."""

        fs = features_for_doc(message.get("spacy_doc"))
        features = self._combine_with_existing_text_features(message, fs)
        message.set("text_features", features)
